i=1
while i<20:
    j=1
    while j<20:
        mid = 10
        if i<10:
            if j>mid-i and j<mid+i:
                print '*',
            else:
                print " ",
            j+=1
        else:
            if j>i-mid and j<20+mid-i:
                print "*",
            else:
                print ' ',
            j+=1
    i+=1